An estimation of the dimensions of the phycocyanin molecule

✍ Scribed by B. R. Jennings

• Publisher: Wiley (John Wiley & Sons)
• Year: 1968
• Tongue: English
• Weight: 454 KB
• Volume: 6
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1968.360060812

✦ Synopsis

Iiiiowledge of the total particle volume aiid the specific volumes of the constituent polar arid iioiipolar amino acid residues of a globular protein may be used in suitable iiistaiices to estimate the size aiid shape of the macromolecule. Use has beeii made of thc data which is available in the literature for phycocyanin from Plectonema calothricoides, to predict possible models for the monomer and hexamer forms of this protei?

The monomer is well represented by a prolate ellipsoid with semiaxes of 45 and 17A and an approximate molecular weight of 46000. The hexamer is envisaged as the aggregate of six such monomers, in juxtaposition, with their major axes parallel so as to form a closed ring structure of about 268000 molecular weight. These proposed models are consistent with the previously published electron micrographs and hydrodyiiitmic properties of this protein.